Clinical Experience with PureVision2 HD For Astigmatism
Clinical Experience with PureVision2 HD For Astigmatism
Doctors say the lenses are fitted efficiently to fulfill unmet vision & comfort needs
Dr. Quinn: All of us on the panel who are in clinical practice have had experience with the PureVision2 with High Definition Optics For Astigmatism. What are your thoughts on this new contact lens?
Dr. Epstein: I like the stability of it. Stability is very important when we address fluctuating vision, which is a complaint we’ve experienced with toric lenses in the past.
Dr. Marsden: It stabilizes quickly on lens insertion.
Dr. Basinger: The stabilization is quick, so chair time is quick relative to when you can first evaluate the lens at the slit lamp.
Dr. Epstein: Its resting position is very repeatable.
Dr. Marsden: The ultimate visual outcome has been startling. Some doctors only refract to 20/20, but I can consistently get a solid 20/15 with this lens. That is rare for a toric lens, in my experience.
Dr. Quinn: How long do you need to wait before evaluating this lens on the eye?
Dr. Basinger: Not long at all. I insert the lenses in our contact lens room and then walk the patients back to the chair. By the time I let them blink a few times and ask a few more questions about how things feel, I can start checking acuities and they’re ready to go.
Dr. Geffen: We have switched patients out of several different toric lenses to the PureVision2 HD For Astigmatism. Patients immediately say this lens is more comfortable. Also, as Dr. Marsden said, the optics are unsurpassed.
||I’ve done aberrometry over this lens, and the amount of spherical aberration is much lower than with every other toric lens I’ve measured. Patients return and, without my even asking, say their night vision is much better.|
— David Geffen, OD, FAAO
I’ve performed aberrometry over this lens, and the amount of spherical aberration is much lower than with every other toric lens I have measured. Patients return and, without my even asking, say their night vision is much better.
Dr. Quinn: Do they specifically comment on night vision?
Dr. Geffen: Yes.
Dr. Quinn: Have patients had issues handling the lens because of its larger diameter?
Dr. Epstein: I haven’t had anybody complain about handling issues.
Dr. Marsden: No.
Dr. Epstein: One of my general goals in practice is to make sure patients leave seeing better than when they walked in. This lens makes it very easy to achieve that goal.
TORIC LENS OR SPHERICAL EQUIVALENT?
Dr. Quinn: How many of your patients know they have astigmatism?
Dr. Geffen: I think the majority of patients know they have astigmatism, but may think it’s a disease. They’re not sure that it’s part of their prescription.
Dr. Quinn: How do you educate them about astigmatism?
Dr. Epstein: When I describe astigmatism, I say you can have little differences within your one eye, and we need to have two powers to correct it. Otherwise, part of your eye is out of focus when left uncorrected.
Dr. Geffen: My most powerful tool in communicating astigmatism is, after explaining to patients that it’s not a disease, it’s a shape issue, at the end of the refraction, I take the astigmatism correction out and then reintroduce it. They really get that. They may not fully understand astigmatism, but at least they know how it affects them.
||One of my general rules in practice is to make sure patients leave seeing better than when they walked in. This lens makes it very easy to achieve that goal.|
— Ami Abel Epstein, OD, FAAO
Dr. Quinn: At what degree of astigmatism do you become uncomfortable fitting a spherical lens?
Dr. Basinger: I changed my mind several months ago, largely because of my daughter. She’s a 4.50D myope with about 0.75D of astigmatism. She had been wearing daily disposable lenses, but when she tried PureVision2 HD For Astigmatism she said “Dad, I can really see out of these” Now, instead of thinking I should gloss over that amount of astigmatism in a similar refraction, I try the new lens to see what it can do.
Dr. Quinn: Speaking of the word “try” in reference to the PureVision2 HD For Astigmatism, we’re all using it in this discussion because we all understand each other, but we should avoid it when talking to patients. Instead, we should communicate clearly the benefits of correcting astigmatism. A demonstration is a powerful way to do that, and then we can say, “We’re going to fit you with a lens that will meet your need.” We’re asking them to pay slightly more for toric lenses compared to spherical lenses, but if we believe in the benefits and convey that belief to our patients, they will know it’s worth it.
Dr. Geffen: I perform a quick test in my office. If a patient has 0.50D or more of astigmatism, I place a trial lens with 0.75D of cylinder in front of that spherical lens and ask if it makes a difference. Most patients say it does and then I tell them we should fit this new lens that has optics specifically designed for this situation.
Dr. Epstein: I usually use a toric lens when an eye has 0.75D of astigmatism or more at the corneal plane, but often I prefer a toric for 0.50D. It depends on the type of astigmatism. Against-the-rule astigmatism degrades vision more. Those patients would rather be left with a quarter diopter with the rule than a half diopter against the rule.
Dr. Quinn: This is supported by research as well. Studies11,12 have shown eyes with both low and moderate astigmatism can obtain improved visual acuity with toric contact lenses.
Dr. Marsden: Improvement doesn’t even have to be lines of improvement to benefit the patient. The improvement can be in the quality of vision. In the past, we taught a four-to-one rule, meaning that for every four diopters of spherical refractive error, the patient can tolerate a diopter of astigmatism. I’ve never been able to find support for that in the literature. In reality, we would never follow that rule with spectacles. Why would we impose that on our contact lens patients, especially given today’s toric lens designs?
Patients have gone through decades of being told their correction options are as good as it gets, and maybe they don’t want the added expense of toric lenses, but once I demonstrate what is possible, it really drives home the point that vision is important. That’s what I love about diagnostic lenses. I put them on and know right away if the lenses will give the patient that “aha” moment. Once they realize what they’ve been missing, they want that clear, sharp vision.
||My daughter is a 4.50D myope with about 0.75D of astigmatism ... when she tried PureVision2 HD For Astigmatism, she said, “Dad, I can really see out of these” Now, instead of thinking I should gloss over that amount of astigmatism in a similar refraction, I try the new lens to see what it can do.
— Keith Basinger, OD
||Improvement doesn’t even have to be lines of improvement to benefit the patient. The improvement can be in the quality of vision. In the past, we taught a four-to-one rule, meaning that for every four diopters of spherical refractive error, the patient can tolerate a diopter of astigmatism. I’ve never been able to find support for that in the literature. In reality, we would never follow that rule with spectacles. Why would we impose that on our contact lens patients, especially given today’s toric lens designs?|
— Harue Marsden, OD, MS, FAAO
INITIAL AND END-OF-DAY COMFORT
Dr. Quinn: Prior to the introduction of the PureVision2 HD For Astigmatism, what had been your experience with toric contact lenses?
Dr. Geffen: Historically, toric lenses have been more uncomfortable than spherical lenses. Now we have this lens that is very stable and has a great edge design. I had been using torics for years and they were fine. They correct astigmatism, but patients would often tell me they see better when they put their eyeglasses on in the evening. Now, with aspheric optics correcting some of the higher-order aberrations, patients are telling me their vision with their contact lenses is better. They’re wearing their lenses longer because they see better with them, and they’re seeing better at night. They’re happier overall. They don’t drop out of lens wear down the line either.
Dr. Quinn: Dr. Vogt provided compelling information about halos and glare. How do you discuss this topic with patients?
Dr. Basinger: We have a video for patients to help explain halos and glare. It talks about high-definition lenses, likening them to the experience of watching high-definition TV and how it makes the image so much sharper and crisp than standard-definition TV. Also, I’m in a suburban area, so many people live out in the country, where street lights are few and far between. They can relate easily when I discuss car headlights coming at them at night.
Dr. Epstein: If patients have large pupils, I ask whether they experience problems with night vision because that’s what we would expect. From there I say we can use newer contact lens technology to address the symptoms they may be experiencing.
Dr. Geffen: Our intake form asks patients if they experience glare or halos, and staff ask again during pre-testing. We perform screening aberrometry on every patient and if I see higher-order aberrations, I use that as the starting point to explain how they can degrade vision and what we can do about it.
||Maybe we have heard the word “comfort” and thought of physical issues, but comfort is broader than that. Visual performance can play into the perception of comfort for the contact lens wearer.|
– Thomas Quinn, OD, MS, FAAO
Another thing I do in the exam room, which is simple but effective, is turn the lights down, put a white dot at the end of the room on the wall with a pen light, and ask patients to describe what they see while they’re wearing their current lenses. The ones who have spherical aberration will often tell me they see a “flare” or “a glow around the light.” Then I insert the new lenses with the aspheric optics and we repeat the process. Right away, patients usually say “wow that light is now nice and pinpoint”
Dr. Quinn: Are we creating a problem because we have a solution? Are glare and halos a real problem for patients? Don’t they typically drop out of lens wear because of comfort?
Dr. Marsden: But is it visual comfort or the sensation within the eye? If I’m a patient, maybe I don’t know what you mean by comfort. All I know is at the end of the day, I have wrinkles from squinting and then a headache or some kind of eye strain due to vision issues.
|Easy Fit With Fewer Lens Alignment Markings|
|Dr. Quinn: In designing its new contact lens, the PureVision2 with High Definition Optics For Astigmatism, Bausch + Lomb reduced the number of edge markings from three to one to enhance comfort for patients. When we fit the lens, where should the mark be to indicate how the lens is orienting on the eye?|
Dr. Marsden: From the academic standpoint, we teach students LARS (left add, right subtract), that lenses are going to rotate, and they are mathematically adjusting for that rotation with LARS. Yet, after they graduate, the number-one call to consultation lines is practitioners annoyed that the line is not at 6 o’clock. They’re thinking because they made the mathematical adjustment, the line is going to go to 6 o’clock. It’s not. The power axis orientation has been compensated so that when the lens rotates, the power axis is where it needs to be. The lens should still rotate to wherever it stabilized at the initial fit. If it doesn’t, or if it’s variable, then stability is an issue. I haven’t experienced a stability problem with PureVision2 HD For Astigmatism at all.
Dr. Quinn: A toric lens can rotate as long as it rotates in the same direction, to the same degree, each time?
Dr. Marsden: Yes, correct.
Dr. Quinn: So we’re not looking for a mark to be at 6 o’clock, although often with PureVision2 HD For Astigmatism it is?
Dr. Marsden: It doesn’t have to be at 6 o’clock, but it’s pretty darn close.
Dr. Quinn: How easy is it to see the marking, now that it’s a single mark?
Dr. Basinger: You may have to pull down a patient’s eyelid, but other than that, it’s easy to see.
Dr. Geffen: I have no problem with the visibility of the mark.
Dr. Epstein: Same here.
Dr. Quinn: I see having just one mark as a benefit because in the past when a lens would rotate I have pulled the lid down and seen a mark I thought was the middle mark, but in fact it was one of the edge marks.
Dr. Marsden: That would be a 30º differential.
Dr. Quinn: Yes, I would be assessing the lens to be 30º off from where it really is. In many ways, it’s simpler to have just one lens marking.
Dr. Geffen: The NSIGHT Study included a large number of people — 3,800. It showed patients’ number one concern to be vision. Comfort was down the list in terms of relative importance, because when patients have to choose, they pick vision, and most contact lenses are, in general, comfortable for most patients.
In my practice, I don’t see many contact lens wearers dropping out because they have comfort problems. Drop out occurs as they age and their prescriptions start to change; perhaps they develop some presbyopia. I think if we can keep the optics crisper, we can keep our patients happier.
||I tell patients they may notice a difference in how the lens feels in their eyes. I point out, however, that it’s the same as getting a new ring or watch — anything new you might put on
It feels differently than your old one at first, but in a week or so, you don’t even notice it’s there.|
– Keith Basinger, OD
Dr. Quinn: Maybe we, as a profession, have heard the word “comfort” and thought of physical issues, but comfort is broader than that. Visual performance can play into the perception of comfort for the contact lens wearer.
Dr. Epstein: I’ve been getting a positive response on the PureVision2 HD For Astigmatism on initial comfort and on end-of-day comfort at follow-up.
Dr. Geffen: Yes, the comfort feedback has been excellent. The edge design is impressive. With some edge designs, I feel as if I have to be careful judging the movement of the lens. Some edges tend to clamp and bind to the conjunctiva, and even though the lens will move a millimeter, if I see the conjunctiva moving a millimeter, I’m not going to get adequate transport of oxygen and fluid and waste material in and out from behind the lens. This new edge design has really incorporated great comfort but also good movement, and it doesn’t bind.
Dr. Quinn: It’s a tall order, asking a lens to move but not rotate. Is the PureVision2 HD For Astigmatism delivering on that?
Dr. Marsden: Yes. I think we had become used to tolerating less movement, especially with some silicone hydrogel materials because more oxygen was getting through the lens. But we still have the issue of tear exchange and making sure it isn’t stagnant under the lens. This lens helps in both areas.
BENEFITS FOR PATIENTS AND DOCTORS
Dr. Quinn: What else has stood out for you with the PureVision2 HD For Astigmatism lenses?
Dr. Marsden: Definitely the improved comfort.
Dr. Epstein: The stability.
Dr. Geffen: The lens fits a very wide range of patients and it stabilizes quickly on the full range of cases. The first lens I put in is usually the lens I dispense because I don’t have to make any axis adjustment. For efficiency in the trenches, that’s a wonderful benefit.
Dr. Quinn: How about the diagnostic set? What can practices expect?
Dr. Basinger: It’s been fantastic. Everything I need is in there. The chair time is almost the same as that for fitting a spherical lens. It just fits.
Dr. Marsden: The fitting set is nice and compact, while still being comprehensive. I’ve had initial trial sets in the past where we go to pull a lens and because of the volume it’s not there. I haven’t had that issue with this.
Dr. Epstein: To me, fitting the PureVision2 HD For Astigmatism is no more difficult than fitting a spherical contact lens.
Dr. Geffen: It’s very straightforward. I’m amazed by some of my peers who say they don’t like fitting astigmatic lenses. If they haven’t in the past, this is the lens for them. With the straightforward usage and great fitting set, they should get on the train.
Dr. Quinn: So practitioners don’t have to feel like they need to be contact lens specialists to fit this kind of lens?
Dr. Marsden: No.
Dr. Quinn: Let’s say you recognize that patients with low levels of astigmatism can benefit from a toric contact lens. When a patient who has already been wearing a toric lens and seems happy presents in your chair, do you switch him to the new lens design?
Dr. Basinger: My patients almost expect me to change something because I’m always talking about something new. Plus, they’re so used to new things (like iPhone apps), they want to know about them.
Dr. Quinn: And what benefits do you tell them they would get from making the switch?
Dr. Basinger: With the PureVision2 with HD lenses, it’s the vision, the clarity and stability of it, how well they see.
Dr. Geffen: Also, when we’re able to go that extra yard and give patients 20/15 or even 20/12 vision, I think it can make an enormous difference in their lives. They want that crisper vision for their active lifestyles, and it gets them excited about referring patients to me.
Dr. Quinn: Do we need to prepare patients for any adjustments as they switch from another toric lens to this one?
Dr. Basinger: I tell patients they may notice a difference in how the lens feels in their eye. I point out, however, that it’s the same as getting a new ring or watch, anything new you might put on. It feels differently than your old one at first, but in a week or so, you don’t even notice it’s there.
Dr. Epstein: In a slightly different scenario, switching patients from a spherical lens to a toric, I tell them they might have an awareness of the toric at first. I had a patient come in with headaches. We fit her in a toric lens in one eye because she needed it, but the other didn’t. She commented that her husband had tried toric lenses but could never wear them because of comfort issues. At follow-up, she reported more awareness of the toric lens, but said her vision and headaches were so much better that she wanted to continue with it.
||We’re able to go that extra yard and give patients 20/15 or even 20/12 vision. I think it can make an enormous difference in their lives. They want that crisper vision for their active lifestyles, and it gets them excited about referring patients to me.|
– David Geffen, OD, FAAO
PROVIDING PATIENTS WITH THE WHOLE PACKAGE
Dr. Quinn: To summarize all we’ve discussed, I would say that we all agree that the PureVision2 HD For Astigmatism is not a difficult or time-consuming lens to fit, and it allows our patients with astigmatism to not have to compromise between comfort and clear vision. In other words, for practitioners to use comfort as an excuse for fitting spherical lenses when torics would be more beneficial to patients is no longer acceptable.
By utilizing this new lens in our practices, we’re better able to meet patient needs, which takes our practices up a notch.
||I’m amazed by some of my peers who say they don’t like fitting astigmatic lenses. If they haven’t in the past, this is the lens for them. With the straightforward usage and great fitting set, they should get on the train.|
– David Geffen, OD, FAAO
Dr. Marsden: We can actually exceed patients’ needs because I don’t think they realize how good their vision can be. It’s time we take back the refraction. We shouldn’t stop at a certain line of acuity without identifying the best vision each patient can experience. When we do that, it’s what brings our patients back to us.
Dr. Geffen: Yes, perhaps we’ve forgotten that more than 90% of the patients who come into our offices do so in order to see better. I would add that this new toric lens has great comfort as well as absolutely the best optics of any toric lens that we can put on our patients’ eyes.
Dr. Marsden: We touched on this earlier, but it’s worth repeating. Someone said, “It’s time to put vision back into vision care.” I take that to mean we underestimate our patients’ desire to see well. This is perhaps because we’ve had products in the past that gave them 20/20 or 20/25 vision and they were happy. But the reality is that we can give them better vision. Even if their acuity is the same, we can enhance the quality of vision. So we need to realize 20/happy isn’t good enough anymore. We’ve got to provide vision that is the best it can be.
DELIVERING WHAT PATIENTS NEED AND WANT
When fitting patients with toric contact lenses, it is important to consider all aspects of successful contact lens wear: vision, comfort and health. Patients are looking for contact lenses that offer crisp, consistently clear vision throughout the day without compromising comfort. The lens design of PureVision2 HD For Astigmatism combines High Definition Optics, Auto-Align Design, and ComfortMoist Technology to provide clear, crisp vision all day without compromising the comfort that patients desire. CLS
|1. Needs, Symptoms, Incidence, Global Eye Health Trends (NSIGHT) Study. Market Probe Europe. December 2009.|
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3. Mack CJ, Rah MJ. Visual Benefits of Highest Importance to Eye Care Professionals and Patients When Choosing Contact Lenses for Astigmatism. Poster presented at American Academy of Optometry annual meeting, October 2011, Boston, Mass.
4. Health Products Research, Q3 2005.
5. Astigmatism: Incidence & Barriers. Decision Analyst; December 2008.
6. Thibos LN, Hong X, Bradley A, Cheng X. Statistical variation of aberration structure and image quality in a normal population of healthy eyes. J Opt Soc Am A Opt Image Vis Sci 2002;19(12):2329-2348.
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8. Cox and Kingston. Wavefront aberrations of the eye and their influence on soft contact lens design. Review of Cornea and Contact Lenses; Oct 2011.
9. Results from a 20-investigator, multi-site cross-over study of PureVision2 HD For Astigmatism and PureVision Toric lenses A total of 292 subjects completed the study. Data on file at Bausch + Lomb.
10. Results from a study of five (5) lenses each of PureVision2 For Astigmatism, Biofinity Toric, Air Optix For Astigmatism, and ACUVUE Oasys for Astigmatism of powers -1.00D -0.75D x 180 and -5.00D -0.75D x 180. Measurements were obtained on the SHS Inspect Ophthalmic Instrument from Optocraft Gmbh over a 6 mm aperture size. Lenses were immersed during measurement in a cuvette filled with buffered saline. The average values were offset by +0.15 µm of spherical aberration (population average: Thibos LN, et al. J Opt Soc Am A. 2002; 19:2329-2348). Data on file at Bausch + Lomb.
11. Richdale K, Berntsen DA, Mack CJ, Merchea MM, Barr JT. Visual acuity with spherical and toric soft contact lenses in low-to-moderate astigmatic eyes. Optom Vis Sci 2007; 84(10): 969-975.
12. Bayer, Young. Fitting low astigmats with toric soft contact lenses: what are the benefits and how easily it is achieved? Poster presented during the December 2005 annual meeting of the Academy of Optometry.
Contact Lens Spectrum, Volume: , Issue: March 2012, page(s): 8 - 14